Description of the CERN SPS data on the Landau-Pomeranchuk-Migdal effect for photon bremsstrahlung in quantum regime

We analyze within the light-cone path integral approach [4] the recent CERN SPS data [19] on the Landau-Pomeranchuk-Migdal effect for photon bremsstrahlung in quantum regime from 149, 207, and 287 GeV electrons. Calculations have been carried out treating accurately the Coulomb effects and including the inelastic processes. Comparison with experiment is performed accounting for multi-photon emission. Our results are in good agreement with the data. 1. Recently much attention has been attracted to suppression of radiation processes in media due to multiple scattering (the Landau-Pomeranchuk-Migdal (LPM) effect [1, 2]) both in QED [3, 4, 5, 6, 7, 8] and QCD [9, 10, 4, 11] (for recent reviews, see [12, 13]). In QED new interest in the LPM effect stems from the first accurate measurements of the LPM suppression by the SLAC E-146 collaboration [14] for photon bremsstrahlung from 8 and 25 GeV electrons. A detailed analysis of these high statistics data requires more accurate calculations than that perform by Migdal [2] within the Fokker-Planck approximation. The interest in the LPM effect in QCD is connected with the study of parton energy loss in a hot QCD matter which can be produced in high energy AAcollisions at RHIC and LHC. In [4] (see also [6, 15, 16]) we have developed a new approach to the LPM effect, which